Electronic Structure and High Magnetic Properties of (Cr, Co)-codoped 4H–SiC Studied by First-Principle Calculations

• Main Authors: Mengyu Zhang, Jingtao Huang, Xiao Liu, Long Lin, Hualong Tao
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Crystals
• Subjects: dilute magnetic semiconductor; 3<i>d</i> transition metal; magnetism; 4H–SiC; density functional theory
• Online Access: https://www.mdpi.com/2073-4352/10/8/634

The electronic structure and magnetic properties of 3<i>d</i> transition metal (Cr, Co)-codoped 4H–SiC were studied by density functional theory within GGA methods. The results show that all doped magnetic atoms have high magnetic properties in both Cr-doped and Co-doped 4H–SiC, resulting in the net magnetic moments of 3.03, 3.02 <inline-formula> <math display="inline"> <semantics> <msub> <mi mathvariant="sans-serif">μ</mi> <mi>B</mi> </msub> </semantics> </math> </inline-formula> for Si<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>35</mn> </msub> </semantics> </math> </inline-formula>CrC<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>36</mn> </msub> </semantics> </math> </inline-formula> and Si<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>35</mn> </msub> </semantics> </math> </inline-formula>CoC<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>36</mn> </msub> </semantics> </math> </inline-formula>. The electronic density of states reaches the peak at Fermi level, which is beneficial to the electronic transitions, indicating that Cr-doped 4H–SiC is a semi-metallic material. In addition, the magnetic properties of (Cr, Co)-codoped 4H–SiC were also calculated. The results show that the (Cr, Co)-codoped 4H–SiC system has more stable ferromagnetic properties with <inline-formula> <math display="inline"> <semantics> <mrow> <mo>Δ</mo><msub><mi>E</mi> <mrow> <mi>F</mi> <mi>M</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula> of −244.3 meV, and we estimated <i>T</i><inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mi>C</mi> </msub> </semantics> </math> </inline-formula> of about 470.8 K for the (Cr, Co)-codoped 4H–SiC system. The (Cr, Co)-codoped 4H–SiC can be ferromagnetic through some mechanism based on hybridization between local Cr:3<i>d</i>, Co:3<i>d</i> and C:2<i>p</i> states. These interesting discoveries will help promote the use of excellent SiC-based nanomaterials in spintronics and multi-function nanodevices in the near future.